Look for the cpu “ready” counter which is a percentage of time that the virtual machine was ready, but could not get scheduled to run on the physical CPU. CPU ready time is dependent on the number of virtual machines on the host and their CPU loads.

These are the peak / average figures to watch for in vmware performance graphs. Anything above 5% cpu ready time is worth fixing. (Note : the sampling rate is different depending on which view you are looking at)